Unidirectional transmission of single photons under non-ideal chiral photon-atom interactions

TL;DR

This paper proposes a method for achieving perfect unidirectional single-photon transmission in a non-ideal chiral waveguide system using a driven V-type atom, enhancing quantum network communication.

Contribution

It introduces a scheme utilizing external microwave driving and photon interference to realize complete unidirectional photon transmission despite non-ideal interactions.

Findings

Achieves perfect unidirectional photon transmission with contrast of 1.

Enhances transmission probabilities through constructive interference.

Maintains high transmission contrast even with atomic dissipation.

Abstract

Single-photon transport in non-ideal chiral photon-atom interaction structures generally contains information backflow and thus limits the capabilities to transfer information between distant emitters in cascaded quantum networks. Here, in the non-ideal chiral case, a V -type atom coupled to a waveguide is proposed to realize completely unidirectional transmission of the single photons in a superposition state of different frequencies. A microwave field is introduced to drive the two excited states of the atom and results in photon conversion between two transitions. By adjusting the Rabi frequency and the phase of the external driving field, the transport behaviors of incident photons with specific frequencies can be optimized to complete transmission or reflection. Based on the constructive interferences between photons from different traveling paths, the transmission probabilities of the specific-frequency photons could be enhanced. Due to photon conversions with compensating the dissipations and ensuring the complete destructive interference, the ideal unidirectional transmission contrast can be maintained to 1, even when the atom has dissipations into the non-waveguide modes.